Jamming GPS is the loud option. Spoofing is the one that works.

In short: a jammer removes the satellite signal and the receiver knows something is wrong, so the platform falls back to inertial navigation. A spoofer feeds a false but plausible position that the receiver accepts without complaint, which is why modern navigation defence is built around detecting lies rather than detecting noise.

Ask most people how you defeat a guided drone and they describe a jammer: raise the noise floor, drown the satellite signal, watch the aircraft wander. That part is true and it is cheap. It is also the version the target notices immediately.

קראו גם: The missile does not pick the target. The system behind it does. · Laser air defense: the weapon that changes the cost of every intercept · Most drones are stopped without a single shot fired

A satellite receiver measures signals arriving from roughly 20,000 kilometres away at a power level far below the background noise. Overwhelming it takes very little transmitter power at short range. The moment it happens, the receiver reports a loss of fix, the autopilot switches to its inertial unit, and a well built platform keeps flying its route with slowly growing error.

The quiet attack

Spoofing does the opposite of denial. The attacker transmits a synthetic constellation signal, slightly stronger than the real one, then walks the receiver away from truth in small steps. No alarm fires. The autopilot believes it is exactly where the false solution says it is, and every correction it makes afterwards is obedient and wrong.

This is not theoretical. Civil aviation authorities including EASA have issued repeated safety bulletins about GNSS interference and spoofing near conflict regions, where crews have seen position jumps of tens of kilometres and false terrain warnings at cruise altitude. Israeli traffic around Ben Gurion dealt with sustained regional GPS interference in 2019, well before the current wave.

Three attacks that get confused with each other

The third row is the expensive one. Denial costs the operator a mission. A hijacked navigation solution can deliver a platform, or an intercept, to the wrong coordinates while every display looks healthy.

What actually hardens a platform

Defence here is layered in the same way an air picture is, and for the same reason: no single sensor deserves blind trust. The same principle drives why one interceptor never defends a country on its own.

• Controlled reception pattern antennas that steer a null toward the interfering direction
• Tight coupling between the satellite receiver and the inertial unit, so a sudden position jump is rejected instead of accepted
• Multi-constellation reception, including Galileo, whose Open Service Navigation Message Authentication lets a receiver verify the message actually came from the satellite
• Terrain or visual matching for the final approach phase, which no radio attack can touch
• Clock holdover good enough that the receiver notices time being dragged
• Logging of carrier to noise ratios, because a spoofer usually arrives slightly too strong and too uniform

Notice how much of that is filtering rather than firing. It is the same habit that lets most drones be stopped without a shot, and the same habit behind a radar that spends its processing budget deleting almost everything it sees.

The cost asymmetry cuts both ways

A crude jammer can be assembled from commercial parts for a few hundred dollars. A credible spoofer needs a software defined radio, current almanac data and someone who understands receiver tracking loops, which is a different league of attacker but still far below the cost of an interceptor. Hardening a fleet of platforms, meanwhile, is a fixed one time engineering cost per airframe.

The operational test is simple. Take your platform, cut the satellite signal completely, and measure how far it drifts over ten minutes of inertial only flight. Then run the harder test: feed it a false position and see whether anything in the system says no. Background on the attack family is summarised in the Wikipedia entry on spoofing attacks.